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author | H. Peter Anvin <hpa@zytor.com> | 2008-08-12 10:34:51 -0700 |
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committer | H. Peter Anvin <hpa@zytor.com> | 2008-08-12 10:34:51 -0700 |
commit | a19312bee0a7cef7cfa0fa109312600cc2da36f7 (patch) | |
tree | 19bab255da0e9d14a7dd1fb4a6db7587da848834 /gpxe/src/drivers/net/virtio-net.c | |
parent | 7552258bacc4ef63f7ad40baf26162a1bcf81f78 (diff) | |
download | syslinux-a19312bee0a7cef7cfa0fa109312600cc2da36f7.tar.gz |
Merge updated version of the gPXE code
Merge gPXE up to upstream git version gpxe-0.9.3-release-197-gff2b6a5
(ff2b6a512d7a4f351e48dc9a042099a1010342a3).
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'gpxe/src/drivers/net/virtio-net.c')
-rw-r--r-- | gpxe/src/drivers/net/virtio-net.c | 492 |
1 files changed, 492 insertions, 0 deletions
diff --git a/gpxe/src/drivers/net/virtio-net.c b/gpxe/src/drivers/net/virtio-net.c new file mode 100644 index 00000000..4ec154df --- /dev/null +++ b/gpxe/src/drivers/net/virtio-net.c @@ -0,0 +1,492 @@ +/* virtio-net.c - etherboot driver for virtio network interface + * + * (c) Copyright 2008 Bull S.A.S. + * + * Author: Laurent Vivier <Laurent.Vivier@bull.net> + * + * some parts from Linux Virtio PCI driver + * + * Copyright IBM Corp. 2007 + * Authors: Anthony Liguori <aliguori@us.ibm.com> + * + * some parts from Linux Virtio Ring + * + * Copyright Rusty Russell IBM Corporation 2007 + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + * + */ + +#include "etherboot.h" +#include "nic.h" +#include "virtio-ring.h" +#include "virtio-pci.h" +#include "virtio-net.h" + +#define BUG() do { \ + printf("BUG: failure at %s:%d/%s()!\n", \ + __FILE__, __LINE__, __FUNCTION__); \ + while(1); \ +} while (0) +#define BUG_ON(condition) do { if (condition) BUG(); } while (0) + +/* Ethernet header */ + +struct eth_hdr { + unsigned char dst_addr[ETH_ALEN]; + unsigned char src_addr[ETH_ALEN]; + unsigned short type; +}; + +struct eth_frame { + struct eth_hdr hdr; + unsigned char data[ETH_FRAME_LEN]; +}; + +typedef unsigned char virtio_queue_t[PAGE_MASK + vring_size(MAX_QUEUE_NUM)]; + +/* TX: virtio header and eth buffer */ + +static struct virtio_net_hdr tx_virtio_hdr; +static struct eth_frame tx_eth_frame; + +/* RX: virtio headers and buffers */ + +#define RX_BUF_NB 6 +static struct virtio_net_hdr rx_hdr[RX_BUF_NB]; +static unsigned char rx_buffer[RX_BUF_NB][ETH_FRAME_LEN]; + +/* virtio queues and vrings */ + +enum { + RX_INDEX = 0, + TX_INDEX, + QUEUE_NB +}; + +static virtio_queue_t queue[QUEUE_NB]; +static struct vring vring[QUEUE_NB]; +static u16 free_head[QUEUE_NB]; +static u16 last_used_idx[QUEUE_NB]; +static u16 vdata[QUEUE_NB][MAX_QUEUE_NUM]; + +/* + * Virtio PCI interface + * + */ + +static int vp_find_vq(struct nic *nic, int queue_index) +{ + struct vring * vr = &vring[queue_index]; + u16 num; + + /* select the queue */ + + outw(queue_index, nic->ioaddr + VIRTIO_PCI_QUEUE_SEL); + + /* check if the queue is available */ + + num = inw(nic->ioaddr + VIRTIO_PCI_QUEUE_NUM); + if (!num) { + printf("ERROR: queue size is 0\n"); + return -1; + } + + if (num > MAX_QUEUE_NUM) { + printf("ERROR: queue size %d > %d\n", num, MAX_QUEUE_NUM); + return -1; + } + + /* check if the queue is already active */ + + if (inl(nic->ioaddr + VIRTIO_PCI_QUEUE_PFN)) { + printf("ERROR: queue already active\n"); + return -1; + } + + /* initialize the queue */ + + vring_init(vr, num, (unsigned char*)&queue[queue_index]); + + /* activate the queue + * + * NOTE: vr->desc is initialized by vring_init() + */ + + outl((unsigned long)virt_to_phys(vr->desc) >> PAGE_SHIFT, + nic->ioaddr + VIRTIO_PCI_QUEUE_PFN); + + return num; +} + +/* + * Virtual ring management + * + */ + +static void vring_enable_cb(int queue_index) +{ + vring[queue_index].avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT; +} + +static void vring_disable_cb(int queue_index) +{ + vring[queue_index].avail->flags |= VRING_AVAIL_F_NO_INTERRUPT; +} + +/* + * vring_free + * + * put at the begin of the free list the current desc[head] + */ + +static void vring_detach(int queue_index, unsigned int head) +{ + struct vring *vr = &vring[queue_index]; + unsigned int i; + + /* find end of given descriptor */ + + i = head; + while (vr->desc[i].flags & VRING_DESC_F_NEXT) + i = vr->desc[i].next; + + /* link it with free list and point to it */ + + vr->desc[i].next = free_head[queue_index]; + wmb(); + free_head[queue_index] = head; +} + +/* + * vring_more_used + * + * is there some used buffers ? + * + */ + +static inline int vring_more_used(int queue_index) +{ + wmb(); + return last_used_idx[queue_index] != vring[queue_index].used->idx; +} + +/* + * vring_get_buf + * + * get a buffer from the used list + * + */ + +static int vring_get_buf(int queue_index, unsigned int *len) +{ + struct vring *vr = &vring[queue_index]; + struct vring_used_elem *elem; + u32 id; + int ret; + + elem = &vr->used->ring[last_used_idx[queue_index] % vr->num]; + wmb(); + id = elem->id; + if (len != NULL) + *len = elem->len; + + ret = vdata[queue_index][id]; + + vring_detach(queue_index, id); + + last_used_idx[queue_index]++; + + return ret; +} + +static void vring_add_buf(int queue_index, int index, int num_added) +{ + struct vring *vr = &vring[queue_index]; + int i, avail, head; + + BUG_ON(queue_index >= QUEUE_NB); + + head = free_head[queue_index]; + i = head; + + if (queue_index == TX_INDEX) { + + BUG_ON(index != 0); + + /* add header into vring */ + + vr->desc[i].flags = VRING_DESC_F_NEXT; + vr->desc[i].addr = (u64)virt_to_phys(&tx_virtio_hdr); + vr->desc[i].len = sizeof(struct virtio_net_hdr); + i = vr->desc[i].next; + + /* add frame buffer into vring */ + + vr->desc[i].flags = 0; + vr->desc[i].addr = (u64)virt_to_phys(&tx_eth_frame); + vr->desc[i].len = ETH_FRAME_LEN; + i = vr->desc[i].next; + + } else if (queue_index == RX_INDEX) { + + BUG_ON(index >= RX_BUF_NB); + + /* add header into vring */ + + vr->desc[i].flags = VRING_DESC_F_NEXT|VRING_DESC_F_WRITE; + vr->desc[i].addr = (u64)virt_to_phys(&rx_hdr[index]); + vr->desc[i].len = sizeof(struct virtio_net_hdr); + i = vr->desc[i].next; + + /* add frame buffer into vring */ + + vr->desc[i].flags = VRING_DESC_F_WRITE; + vr->desc[i].addr = (u64)virt_to_phys(&rx_buffer[index]); + vr->desc[i].len = ETH_FRAME_LEN; + i = vr->desc[i].next; + } + + free_head[queue_index] = i; + + vdata[queue_index][head] = index; + + avail = (vr->avail->idx + num_added) % vr->num; + vr->avail->ring[avail] = head; + wmb(); +} + +static void vring_kick(struct nic *nic, int queue_index, int num_added) +{ + struct vring *vr = &vring[queue_index]; + + wmb(); + vr->avail->idx += num_added; + + mb(); + if (!(vr->used->flags & VRING_USED_F_NO_NOTIFY)) + vp_notify(nic, queue_index); +} + +/* + * virtnet_disable + * + * Turn off ethernet interface + * + */ + +static void virtnet_disable(struct nic *nic) +{ + int i; + + for (i = 0; i < QUEUE_NB; i++) { + vring_disable_cb(i); + vp_del_vq(nic, i); + } + vp_reset(nic); +} + +/* + * virtnet_poll + * + * Wait for a frame + * + * return true if there is a packet ready to read + * + * nic->packet should contain data on return + * nic->packetlen should contain length of data + * + */ +static int virtnet_poll(struct nic *nic, int retrieve) +{ + unsigned int len; + u16 token; + struct virtio_net_hdr *hdr; + + if (!vring_more_used(RX_INDEX)) + return 0; + + if (!retrieve) + return 1; + + token = vring_get_buf(RX_INDEX, &len); + + BUG_ON(len > sizeof(struct virtio_net_hdr) + ETH_FRAME_LEN); + + hdr = &rx_hdr[token]; /* FIXME: check flags */ + len -= sizeof(struct virtio_net_hdr); + + nic->packetlen = len; + memcpy(nic->packet, (char *)rx_buffer[token], nic->packetlen); + + /* add buffer to desc */ + + vring_add_buf(RX_INDEX, token, 0); + vring_kick(nic, RX_INDEX, 1); + + return 1; +} + +/* + * + * virtnet_transmit + * + * Transmit a frame + * + */ + +static void virtnet_transmit(struct nic *nic, const char *destaddr, + unsigned int type, unsigned int len, const char *data) +{ + /* + * from http://www.etherboot.org/wiki/dev/devmanual : + * "You do not need more than one transmit buffer." + */ + + /* FIXME: initialize header according to vp_get_features() */ + + tx_virtio_hdr.flags = 0; + tx_virtio_hdr.csum_offset = 0; + tx_virtio_hdr.csum_start = 0; + tx_virtio_hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE; + tx_virtio_hdr.gso_size = 0; + tx_virtio_hdr.hdr_len = 0; + + /* add ethernet frame into vring */ + + BUG_ON(len > sizeof(tx_eth_frame.data)); + + memcpy(tx_eth_frame.hdr.dst_addr, destaddr, ETH_ALEN); + memcpy(tx_eth_frame.hdr.src_addr, nic->node_addr, ETH_ALEN); + tx_eth_frame.hdr.type = htons(type); + memcpy(tx_eth_frame.data, data, len); + + vring_add_buf(TX_INDEX, 0, 0); + + /* + * http://www.etherboot.org/wiki/dev/devmanual + * + * "You should ensure the packet is fully transmitted + * before returning from this routine" + */ + + while (vring_more_used(TX_INDEX)) { + mb(); + udelay(10); + } + + vring_kick(nic, TX_INDEX, 1); + + /* free desc */ + + (void)vring_get_buf(TX_INDEX, NULL); +} + +static void virtnet_irq(struct nic *nic __unused, irq_action_t action) +{ + switch ( action ) { + case DISABLE : + vring_disable_cb(RX_INDEX); + vring_disable_cb(TX_INDEX); + break; + case ENABLE : + vring_enable_cb(RX_INDEX); + vring_enable_cb(TX_INDEX); + break; + case FORCE : + break; + } +} + +static void provide_buffers(struct nic *nic) +{ + int i; + + for (i = 0; i < RX_BUF_NB; i++) + vring_add_buf(RX_INDEX, i, i); + + /* nofify */ + + vring_kick(nic, RX_INDEX, i); +} + +static struct nic_operations virtnet_operations = { + .connect = dummy_connect, + .poll = virtnet_poll, + .transmit = virtnet_transmit, + .irq = virtnet_irq, +}; + +/* + * virtnet_probe + * + * Look for a virtio network adapter + * + */ + +static int virtnet_probe(struct nic *nic, struct pci_device *pci) +{ + u32 features; + int i; + + /* Mask the bit that says "this is an io addr" */ + + nic->ioaddr = pci->ioaddr & ~3; + + /* Copy IRQ from PCI information */ + + nic->irqno = pci->irq; + + printf("I/O address 0x%08x, IRQ #%d\n", nic->ioaddr, nic->irqno); + + adjust_pci_device(pci); + + vp_reset(nic); + + features = vp_get_features(nic); + if (features & (1 << VIRTIO_NET_F_MAC)) { + vp_get(nic, offsetof(struct virtio_net_config, mac), + nic->node_addr, ETH_ALEN); + printf("MAC address "); + for (i = 0; i < ETH_ALEN; i++) { + printf("%02x%c", nic->node_addr[i], + (i == ETH_ALEN - 1) ? '\n' : ':'); + } + } + + /* initialize emit/receive queue */ + + for (i = 0; i < QUEUE_NB; i++) { + free_head[i] = 0; + last_used_idx[i] = 0; + memset((char*)&queue[i], 0, sizeof(queue[i])); + if (vp_find_vq(nic, i) == -1) + printf("Cannot register queue #%d\n", i); + } + + /* provide some receive buffers */ + + provide_buffers(nic); + + /* define NIC interface */ + + nic->nic_op = &virtnet_operations; + + /* driver is ready */ + + vp_set_features(nic, features & (1 << VIRTIO_NET_F_MAC)); + vp_set_status(nic, VIRTIO_CONFIG_S_DRIVER | VIRTIO_CONFIG_S_DRIVER_OK); + + return 1; +} + +static struct pci_device_id virtnet_nics[] = { +PCI_ROM(0x1af4, 0x1000, "virtio-net", "Virtio Network Interface"), +}; + +PCI_DRIVER ( virtnet_driver, virtnet_nics, PCI_NO_CLASS ); + +DRIVER ( "VIRTIO-NET", nic_driver, pci_driver, virtnet_driver, + virtnet_probe, virtnet_disable ); |